This disclosure relates to controlling stability in acoustic noise reducing (ANR) devices, and in particular ANR devices using an in-ear form factor.
U.S. Pat. Nos. 8,073,150 and 8,073,151, incorporated here by reference, describe a digital signal processor for use in an ANR system that allows the system designer to configure numerous aspects of the system. In particular, the designer can configure the signal flow topology within the signal processor, and the coefficients of filters applied to signals at numerous points within the topology. Such designs can also be implemented in analog circuits.